Secondary ion microscopes are mostly used to provide laterally resolved atomic surface and/or in-depth concentration profiles with high sensitivity. In general, the target surface to be analyzed is sequentially bombarded by a primary ion beam which causes charged and neutral particles to be emitted. The emitted secondary ions are then extracted from the target into the ion optical system which projects a magnified ion image of the target surface onto a suitable detector. State-of-the-art ion microscopes use mass dispersing optical systems, and the secondary ion image of each secondary ion type has to be evaluated separately.
Various designs and proposals for time of flight mass spectrometers have been described in the literature including the papers in the International Journal of Mass Spectrometry and Ion Physics by W. P. Poschenrieder, "Multiple-Focusing Time-Of-Flight Mass Spectrometers Part II. TOFMS With Equal Energy Acceleration", Vol. 9, pp 357-373 (1972); by G. H. Oetjen et al, "Focussing Errors of a Multiple-Focussing Time-Of-Flight Mass Spectrometer With an Electrostatic Sector Field", Vol. 16, pp 353-367 (1975); and by H. Wollnik et al, "A Q-Value For Energy-Focused, Time-Of-Flight Spectrometers, Vol. 37, pp 209-225 (1981) and in the International Journal of Mass Spectrometry and Ion Processes by T. Sakurai et al, "Ion Optics for Time-Of-Flight Mass Spectrometers with Multiple Symmetry", Vol. 63, pp 273-287 (1985) and by T. Sakurai et al, "A Time-Of-Flight Mass Spectrometer", Vol.66, pp 283-290 (1985).